Be careful what door you walk thru

However, think of this...what is one of the first things you do after you bump your head or pinch a finger by accident? You probably rub it and it feels better, right? Could this be explained by the gate control theory? Well, rubbing your bumped head or pinched finger would activate non-nociceptive touch signals carried into the spinal cord by large nerve fibers. According to the theory, the activity in the large nerve fibers would activate the inhibitory interneuron that would then block the projection neuron and therefore block the pain.

The gate control theory of pain, put forward by Ronald Melzack (a Canadian psychologist) and Patrick David Wall (a British physician) in 1962,[1] and again in 1965,[2] is the idea that the perception of physical pain is not a direct result of activation of nociceptors, but instead is modulated by interaction between different neurons, both pain-transmitting and non-pain-transmitting. The theory asserts that activation of nerves that do not transmit pain signals can interfere with signals from pain fibers and inhibit an individual's perception of pain.

Gate control theory asserts that activation of nerves which do not transmit pain signals, called nonnociceptive fibers, can interfere with signals from pain fibers, thereby inhibiting pain. Afferent pain-receptive nerves, those that bring signals to the brain, comprise at least two kinds of fibers - a fast, relatively thick, myelinated "Aδ" fiber that carries messages quickly with intense pain, and a small, unmyelinated, slow "C" fiber that carries the longer-term throbbing and chronic pain. Large-diameter Aβ fibers are nonnociceptive (do not transmit pain stimuli) and inhibit the effects of firing by Aδ and C fibers.

The peripheral nervous system has centers at which pain stimuli can be regulated. Some areas in the dorsal horn of the spinal cord that are involved in receiving pain stimuli from Aδ and C fibers, called laminae, also receive input from Aβ fibers.[3] The nonnociceptive fibers indirectly inhibit the effects of the pain fibers, 'closing a gate' to the transmission of their stimuli.[3] In other parts of the laminae, pain fibers also inhibit the effects of nonnociceptive fibers, 'opening the gate'.[3]